Locating dogmeat:
Go to the scrapyard, northeast from megaton, over the river, where you'll find the dog.

Unlimited good karma in megaton:
Go to megaton, where you'll find the church for the children of the atom. Go to the priest who is by the bomb or in their building. Give him donations, and you�ll get karma.

Increasing your experience:Set the game's difficulty to very hard; next, hack the computer or do some lock picking. These actions will give you more experience points.

Stowing goods on dead bodies:
Place your own goods onto a corpse and get them later.

Buy Clover the slave girl:
At euology in paradise falls you can buy a slave girl named clover. She costs 1000 caps and uses a knife and sawed off shotgun.

Gifts in megaton:
If you own a house in megaton and have a rating of at least paladin then random people will give you gifts everytime you return to megaton.

Unlock the terrible shotgun:
In evergreen mills near casey smith's gas station kill smiling jack and you will have the terrible shotgun. It does around 80 damage when fully repaired.

Infinite mutant karma:
Go to big town at night; The town will be attacked from a super mutant raiding party; slay each super mutant to acquire more karma.

Conserve your AP:
When battling a foe or group of foes, aim at them in VATS, but don't shoot. You'll keep your AP but still be aiming at the part of the foe's body you were in VATS.

Hidden sniper rifle cache in megaton:
There is a sniper rifle and other supplies hidden in a rock near megaton.

Infinite experience points:
Go to craterside supply in megaton with a few frag mines. Place a mine close to the wall that the mercenary is leaning against. Quickly pick it up to earn 5 experience points. Repeat as desired.

Easy caps:
In the strictly business quest capture susan lancaster and collect the reward. Then speak with her in the slave quarters part of paradise falls. You will need to pickpocket a key from one of the slavers to enter slave quarters. When she asks for help, choose the option "You're a slave. Deal with it.". When you return to grouse he will think you captured her again and reward you. Repeat as desired.

Easy XP and caps:
Save all pre-war books you find and go to the arlington library. At the southeastern corner there is an NPC that will buy them for 100 Caps each. In addition you will gain 10 experience points for each book sold.

Get fat man gun passcode:
Collect all of the keller family transcripts. The fat man gun shoots eight mini-nukes at once.

Prototype medic power armor location:
Set the difficulty to "Very Easy", and go to Old Olney in the northeast section of the map. On the southern-most street of the town is a grate on the sidewalk. Step on it, and it will open out from underneath you. Go through the sewers and you will find a ladder on your left. Keep going straight to find a brotherhood of steel initiate wearing the armor. The armor talks and will inject you with med-X when your limbs are crippled.

T-51b power armor location:
After completing the "You've Gotta Shoot Them In The Head" mission return to Mr. Crowley once you have all four keys. Follow him out of underworld, and take back the keys. Go to fort constantine and enter the little house on the left named the "CO Quarters". Go downstairs, and use the key on the "launch control bunker" door. You will find doors for all the keys. The T-51b is in the last room under glass. Use the computer to free it.
Floating brahim glitch:
Go to Megaton. Down the slope will be a brahim on the right. crouch up beside it after it sees you. Press action on it repeatedly which will push it, making it suddenly float up in the air.